Indianola, Ia. — Sarah Palin has a campaign bus, a horde of screaming fans and now a five-point plan. What else does she need to run for president?

A campaign organization, maybe. But let’s not get bogged down with picky details. There’s no doubt that Palin is a phenomenon. Her 40-minute speech had enough fiery lines to warm up a soggy crowd at the rainy Indianola Balloon Field. She was frequently interrupted with cheers and occasionally with chants of “Sarah! Sarah! Sarah!”

The excitement level ramped up when Palin suggested that a change of administration wasn’t enough to fix what’s wrong in Washington, D.C. The real challenge, she said, is not simply to replace Barack Obama in 2012, “the real challenge is who or what we will replace him with.”

In some ways, she sounded exactly like most of the Republican presidential candidates: shrink government, cut taxes, repeal Obamacare, stop burdensome regulation, remove barriers to domestic energy production. She called for eliminating corporate income taxes, but vowed to close loopholes and end bailouts. America’s exceptional, no apologies, etc.

In other ways, she sounded more like a third-party contender. She focused most of her scorching review of “crony capitalism” and the “permanent political class” on the Obama administration. But, she said, some GOP candidates are also raising “mammoth” amounts of money. “We need to ask them, too what, if anything, do their donors expect in return for their investments,” she said. I’m guessing she’s not pointing the finger at Rick Santorum.

She pleaded with voters to vet candidates’ record. “You must know their ability to successfully reform and actually fix problems that they’re going to claim that they inherited,” she said.

She didn’t include campaign-finance reform as part of her five-point plan. Instead, she offered herself as an example of standing up to special-interests. “I took on a corrupt and compromised political class and their backward dealings with Big Oil,” she said.

One of the big question-marks about Palin when she first started flirting with running was her tolerance for grass-roots campaigning and the accompanying mobs of media. She went a long way toward banishing those with her Iowa State Fair appearance last month, where she signed countless autographs and shook hands for hours. She’s not holding press conferences, but she’ll take a question or two from reporters.

Bob Aschoff of Ankeny said he’s met Palin several times and is a big admirer of her retail-politics skills. She makes eye contact and takes her time when she works the crowd, he said. “It’s just something on a real personal level that you connect with right away,” he said.

It’s easy to mistake rock-star popularity for genuine support for a presidential candidate. Palin had plenty of fans in the audience, but the rally sponsored by the American Tea Party didn’t look much like an Iowa caucus crowd. I met Palin supporters from St. Louis, Nashville and Kansas City before I picked out Aschoff, who had the good sense to be wearing a Hawkeye shirt.

A couple from Carlisle, standing in pouring rain with no umbrellas or raincoats, seemed like the epitome of die-hard tea partiers or Palin fans. Not exactly, Ruth Hammerstrum said. They just came over to see what the tea party is all about. “I’m probably not a Republican, not a Democrat, kind of independent. I just want to make sure I vote for the right person,” she said.

Marylee Vanderpool of Indianola also said it was concern for the country that brought her out to the rally. She doesn’t have a favorite presidential candidate yet. Asked whether Palin should run for president, Vanderpool said, “If that’s where she feels like she needs to go, I’m for it. I think the guys have had a chance – I think it’s time for a woman to step up.”

Aschoff, the Palin supporter from Ankeny, said he believes there is a base of support for Palin in Iowa. It’s just dormant, waiting for her to decide whether to run.

After today’s speech, it seems like they won’t have much longer to wait.